Photographic-printing device



May 22, 1923.

A. G. OGDEN PHOTOGRAPHIC PRINTING DEVICE Filed March 14, 1921 A TTOR/VE Y Patented May 22, 1923.

PATENT OFFICE,

ASHLEY G. OGDEN, 0F BALTIMORE, MARYLAND.

PHOTOGRAPHIC-PRINTING DEVICE.

Application filed March 14, 1921. Serial No. 452,881.

To all whom it may concern:

Be it known that 1, ASHLEY G. OGDEN, a citizen of the United States, and a resident of Baltimore, county of Baltimore, and State of Maryland, have invented certain new and useful Printing Devices, of which the following is a specification.

This invention relates to methods of and devices for printing lithographic plates and has particular reference to ameans tor supporting a metallic sheet from which plates of the general type shown in the patent to Ogden, Reissue. No. 14,517 of September 3, 1918, are photographically produced.

It has been proposed to provide a laterally adjustable and vertically movable plateholder or frame for retaining the sensitized plates which are usually made of zinc or aluminum, the plates being clamped at two opposite margins thereof by metallic clamps forming a part of the frame construction per se. In order, however, to eil'ectively reta-in the edges of the plate it was vfound necessary to dispose the jaws of the clamp at an angle with respect to the main body of the plate so that the clamped portion of the plate was retained between the jaws at an angle with respect to the main body of the plate, the plate thus being'drawn over the lowerjaws of the clamps'eausin it to buckle relatively near its clamps ends thereby tending to cause the plate to present a rolling or uneven surface. This unevenness prevented an intimate contact of the plate under pressure with the negative during the printing operation which sometimes resulted in defective printing.

In order to overcome this objection it was proposed to temporarily mount the sensitized plate upon a suitable resilient material carried by a pressure-board or mount. The

board or mount was adapted to be clamped within a suitable frame in such a manner as to permit the plate to be moved into contact with the negative throughout the entire area of the plate by reason of the lateral adjustability of the frame. By mounting the plate upon the board or mount in a perfectly flatcondition the objection as to the imperfection in the printing was overcome, but a second disadvantage arose in that the plates, they being made of aluminum or Improvements 'in Photographiczinc, would break at their margins when attempting to reclaim them for further use. The breakage resulted from the fact that the plates were bent at their ends when placed on the printing roll to enable them to be secured thereto in the usual manner, and were bent back or flattened when placed on the board or mount for reprinting.

By employing the late-holder provided with the clamps it is o vious that the objection as to breakage of the plates, due to successive bending of the same at their ends, could not be raised, but the imperfection in printing due to bucklin of the plate when clamped, constituted an objection; while on the other hand by employing the pressureboard as a support for the plate the imperfection in printing was avoided, but the objectionable breakage of the plates, by necessarily repeatedly bending them at their ends, consequently arose.-

One of the objects of this invent-ion is to provide an improved means and method by which lithographic plates may be accurately and speedily exposed while retaining the sensitized plate in a flat condition enabling the same to intimately engage the negative throughout the contact area thereof.

A fiuther object of this invention is to provide in a plate-support a means whereby the contact surface of the plate may be held in a perfectly flat condition during the printing operation thereby insuring an intimate surface contact with the negative without necessitating the bending of its ends into the plane of the plate upon removal of the same from the printing roll.

In the accompanying drawing, Figure l is a perspective view or" one form of the support showing the sensitized plate thereon, the sensitized plate being partly broken away and the resilient mounting turned up.

Figure :2 is a fragmentary sectional side view of the same.

The support 1 usually includes a fairly stiii mount or pressure-board 2 which may be constructed of wood rabetted at 3 alon each cross-grain edge to receive the tongue 4- or" an edge member 5 which is adapted to prevent warping of the support. The sensitized plate 6, such as a plate of aluminum or zinc is supported by the resilient layers 7 and 8 in such a manner as to maintain the 'tive' in the printin main body thereof out of contact with the mount 2, the layers 7 and 8 forming collectively an offset upon which the plate 6 is adapted to rest in a flat condition. The layers 7 and 8 serve not only as a means for supporting the main portion of the plate 6 out ofcontact with the mount 2 but also as a means for cushioning the plate 6 when pressure is applied to the mount 2 in the rinting process, the cushioning being efected by reason of the fact that the layer 8 may be formed of a suitable felt whereas the layer 7 may be formed of rubber. The layer of felt is secured to the mount 2 by a suitable adhesive and the layer 7 is secured likewise to the layer of felt 8. The mount or pressure-board 2 may be provided also with a backing 9 preferably formed of rubber and held in position by a suitable adhesive. 1 wish to state here that while the layer of rubber 7 and the resilient layer of felt 8 are permanently secured in position upon the mount 2 the same is not true of the sensitized plate 6,'this being only tem porarily secured to the rubber layer 7 by a suitable cement preferably deposited thereon relatively near the edges thereof so as to permit the plate 6 to be readily removed from the support after exposure.

It'will be noted that the felt 8 and rubber 7 are cut away atopposite ends to provide a clearance for the angularly bent portions 10 of the metallic sensitized surface 6, thereby permitting the metallic sensitized surface 6 to lie perfectly fiat upon the rub her 7, while the bent ends are protected from damage by the adjacent extensions 11 of the support or mount. It is understood that if the felt 8 and rubber 7 were extended to the ed e of the mount 2 it would require a bending of the bent portion 10 from the position shown in Figure,,2 into the plane of the metallic surface 6 in order to enable the metallic sheet 6 to be secured to the rubber 7 in such a manner as to present a smooth or even surface to provide for a uniform and intimate contact with the negaprocess. Those skilled in the art will an erstand that the ends or bent portions 10, once having been straightened for exposure when removed from the printing drum of the ordinary type of lithographing machines, would necessarily have to be bent-againto the osition shown in Figure 2, or to substantial ysuch a position, when theplate is a ain, placed in position on the drum of the ithographing machine.

If aluminum or zinc plates are used, these being preferablek it is obvious that the life of the plate would be limited to a relatively short period.

The support'with its sensitized plate 6 may be readily placed in a suitable plateholder and then set in osition in a machine of the type shown in said Ogden patent with It is apparent that I have succeeded in providing not only a simple and inexpensive means for supporting the sensitized material during exposure, but that I have also made possible the elimination of difficulties heretofore encountered in the production of lithographic plates and in the reclaiming of such for further use without sacrificing any of the advantages of similar devices.

Having thus described one embodiment of my invention, what I claim is:

1. The combination with a mount in the form of a wooden board having stiffening edges running acrom its grain, of a resilient surface thereon adapted to serve as a backing for a sensitized plate.

2.. The combination with a mount adapted to support a sensitized plate, said mount being in the form of awooden board having stiffening edges running across its grain, of a yielding felt surface upon the mount, and means adapted to hold a sensitized plate upon the yielding surface.

3. The combination with a mount in the form of a board, of a yielding felt surface upon the mount, and a rubber surface extending. across the felt surface and adapted to receive a sensitized plate.

4. The combination with a mount in the form of a board, of a yielding felt surface upon the mount, a rubber surface extending across the felt surface and adapted to receive a sensitized plate, and a sheet rubber backing for the board adapted to receive the pressure of a pressure head.

5. The combination with a mount in the form of a wooden board having stiffening edges running across its grain, of a yielding felt surf-ace upon the mount, means adapted to hold a sensitized plate upon the yielding surface, and a sheet rubber backing for the board adapted to receive the pressure f a. pressurehead.

6. In a lithographic plate support, the combination with a mount of a cushioning material disposed upon the mount, certain edges of the cushioning'material being disposed remotely to correspondin edges of the mount; a resilient materia disposed upon the cushioning material, certain edges of the resilient material being disposed remotely to the edges of the mount.

7. In a lithographic plate support, thetit) certain edges of the layer being remote to the corresponding edges of the mount, and

a sheet of backing material adapted to receive the pressure of a pressure head.

8. A support for retaining a sensitized plate in position While being exposed comprising a mount, and a resilient material carried by the mount, the resilient material having certain edges thereof disposed remotely to corresponding edges of the mount and adapted to receive thereupon the plate liaving'certain edges thereof bent over the remotely disposed edges of said resilient material.

9. A support for retaining sensitized plates, having certain of its margins angu larly bent with respect to the main 'body thereof in position while being exposed comprising a mount, a cushioning material carried by the mount and having certain of its margins remotely disposed with respect to corresponding edges of the mount, and a resilient material carried by said cushioning material and having its edges corresponding to the remotely disposed edges of the cushioning material disposed remotely to the corresponding edges of the mount, the resilient material being adapted to re ceive thereupon the sensitized plate having its bent margins overhanging the remotely disposed edges of the cushioning material and the resilient material.

10. A lithographic plate support for supporting a sensitized plate having an edge thereof bent at an angle rliO the body of the plate comprising a mount having an oll'set plate-receiving'portion adapted to receive thereupon the main body of the plate in a flat conditiom the bent edge of the plate being adapted to overhang the offset portion at an angle to the main body or the plate.

11. The combination with a mount adapt-- ed to hold a sensitized metallic plate in a photographic printing machine against the pressure of a pressure head, of yieldable material carried by said mount, resilient material carried by said yieldable material,

- of an adhesive for temporarily attaching the sensitized metallic plate to said resilient material in a fiat condition.

12. A mount adapted to hold a sensitized metallic plate margins of which are bent at an angle with respect to the body thereof, said mount comprising a relatively stid body, a yieldable raised portion carried by said relatively stid body so that the major portion of the sensitized metallic plate may lie thereupon and the angularly bent margins of the plate may overhang said raised portion. l

13. A support for lithographic plates having angularly disposed bent portions comprising a relativelystifi mount adapted to function in connect on withe lithogr phic .to the body thereof comprising -material and corresponding sides of said mount out of the of the plate. I

14:. A laminated support for sensitized metallic lithographic plates adapted to function in connection with a lithographic printing machine, said support comprising a pluralplane of the major portion ity of laminations to one of which the metallic plate is adapted to be attached, one or said laminations being of relatively stiff material whereas the lamination to which the metallic plate is adapted to be attached is in the form of a resilient surface adapted to yield to conform .to any irregularities present in the metallic plate when pressure is applied to the support.

15. A laminated support for sensitised metallic lithographic plates adapted to function in connection with a lithographic printing machine, said support comprising a plurality of laminations to one of which the nietal-lic plate is adapted to be attached, one oi said laminations being of relatively still material Whereas the lamination to which the metallic plate is adapted to be attached is in the form of a resilient surface adapted to yield to conform to any irregularities present in the metallic plate when pressure is applied to the support and means for detachably adhering the metallic plate to said resilient surface in substantially a flat condition.

16. A laminated support for sensitized metallic lithographic plates adapted to function in connection with a lithographic printing machine, said support comprising a plurality of laminations to one of which the metallic plate is adapted to be attached, one of said laminations being of relatively still material Whereas the lamination to which the metallic plate is adapted to be attached is in the form of a resilient surface adapted to yield to conform to any irregularities present in the metallic plate when pressure is applied to the support and a yieldable backing carried by the relatively stiff material to receive the pressure oi the printing machine premure head.

17. A mount adapted to function in con nection with a printing machine and hold in position, a sensitized metallic plat/e, margins of which are bent at an angle with respect a relatively raised porstifl' body, a relatively yieldab 'tion carried by said relatively stifi body and adapted to receive thereupon said plate, 0pposite sides of said raised portion being sufliciently spaced from corresponding sides 5 of said body to permit the angularlybent margins of the plateto overhang said raised portlon whereby only the major portion of said plate is subjected to the pressure of the printing machine pressure head when pressure is applied to the mount. 10

In testimony whereof, I have affixed my signature to this specification.

ASHLEY G. OGDEN. 

